In adddition, the following error is seen when getting Federation information:

[PS] C:\>Get-FederationInformation -domain domain.com
WARNING: An unexpected error has occurred and a Watson dump is being generated: Operation is not valid due to the
current state of the object.
Operation is not valid due to the current state of the object.
+ CategoryInfo : NotSpecified: (:) [Get-FederationInformation], InvalidOperationException
+ FullyQualifiedErrorId : System.InvalidOperationException,Microsoft.Exchange.Management.SystemConfigurationTasks.
GetFederationInformation
+ PSComputerName : server.domain.local

Resolution

Testing the Federation Trust with the mailbox alias of a user reveals a certificate error:

The issue is the certificate NotBefore time is issued with the current time in the Exchange server time zone. If this time zone is ahead of the time zone of the MicrosoftOnline Federation Trust servers, PDT (UTC -7), the certificate will not be valid until it is the NotBefore time in the PDT timezone.

The resolution is to wait until the NotBefore time in UTC -7.

When the following command completes successfully, the trust is valid: